GB2483494A

GB2483494A - Receiver Desiccant Dryer with Filter

Info

Publication number: GB2483494A
Application number: GB1015097.7A
Authority: GB
Inventors: Richard Steven Armsden; Dominic Peter Bennett; Leo Somhorst
Original assignee: Visteon Global Technologies Inc
Current assignee: Visteon Global Technologies Inc
Priority date: 2010-09-10
Filing date: 2010-09-10
Publication date: 2012-03-14
Anticipated expiration: 2030-09-10
Also published as: GB201015097D0; GB2483494B; US20120060546A1; US8959948B2

Abstract

A receiver drier 12 for the refrigeration system of a vehicle air conditioning system has a lower condenser section 31 and an upper sub-cooling section 22 within an elongate housing 26 having an inlet 42 positioned in a first section 31 and an outlet 46 in a second section 36; in use, the inlet receiving condensed refrigerant from the condenser section of a condenser unit (10 fig 1). The drier has a first chamber 56 in the first section containing a desiccant for drying refrigerant from the inlet and a second chamber in the second section containing a filter 80 for filtering the dried condensed refrigerant. The condensed refrigerant is conveyed to the outlet via the filter by a conduit 58 defined between an internal wall 50 and an external wall 28 of the elongate housing, the internal wall separating the desiccant chamber from the conduit.

Description

Receiver Dryer

BACKGROUND

a. Field of the Invention

This invention relates to air conditioning systems and in particular to a receiver dryer for a motor vehicle air conditioning system. More specifically, this invention relates to a receiver dryer having an integral duct.

b. Related Art Most modern vehicles include an air conditioning system which comprises a number of components including a compressor, condenser, receiver dryer, expansion valve and evaporator. The air conditioning system also includes a refrigerant or coolant that flows through each of the components in turn, and undergoes repeated phase changes from a liquid to a gas and back to a liquid.

When the air conditioning system in a vehicle is switched on, liquid refrigerant under pressure flows from the receiver dryer to the expansion valve. Here the refrigerant expands to form a gas, and as it does so, the temperature of the refrigerant drops. The cool gas then enters the evaporator where it absorbs heat from the air that is flowing into the passenger compartment of the vehicle, causing the refrigerant to boil.

The low-pressure refrigerant vapour then enters the compressor. The compressor is typically driven by a drive belt connected to the engine's crankshaft. The compressor compresses the refrigerant vapour and pumps it as a high pressure gas to the condenser. The condenser is typically mounted in front of a vehicle's radiator and comprises a large number of cooling fins surrounding parallel tubes.

As the refrigerant flows through the tubes, air flowing past the fins of the condenser removes heat from the refrigerant, and the refrigerant changes from a gas to a liquid.

The liquid refrigerant then enters the receiver dryer (also called a modulator). The primary function of the receiver dryer is to separate any remaining gas from the liquid refrigerant. The receiver dryer is also used to remove moisture from the refrigerant, and therefore, will typically include a chemical desiccant to remove water from the refrigerant so that it does not freeze in the expansion section of the system. The receiver dryer may further include a filter to remove any dirt from the liquid.

In some vehicle air conditioning systems, a sub-cooled section is located between the receiver dryer and the expansion valve. This sub-cooled section provides additional cooling for the condensed refrigerant to improve system efficiency.

Due to the multiple functions of the receiver dryer, this component is typically complex, and often incorporates a removable insert to allow the desiccant and/or the filter element to be replaced at intervals. The receiver dryer may also include multiple conduits to direct the flow of refrigerant.

It is an object of the present invention to provide a less complex receiver dryer.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a receiver dryer for an air conditioning system for use with a condenser unit having a lower condenser section and an upper super-cooling section, the receiver dryer comprising: -an elongate housing, said housing having opposite ends and an external wall that extends between said ends; -an inlet positioned in a first section of the housing for receivi refrigerant from said lower condenser section of a condenser unit; -an outlet positioned in a second section of the housing for providing dried condensed refrigerant to said upper super-cooling section of a condenser unit; -a partition dividing the first section from the second section such that, in use, the second section is above the first section; -a first chamber in said first section containing a desiccant for drying the refrigerant received from the inlet; -a second chamber in said second section containing a filter for filtering said dried condensed refrigerant provided to the outlet; -a conduit, the conduit having a conduit inlet inside the first chamber for receiving said condensed refrigerant from the first chamber and a conduit outlet inside the second chamber for conveying said received condensed refrigerant upwards past the partition from the first chamber into the second chamber; wherein the housing has within the external wall an internal wall, the internal wall having an elongate central portion extending in the same direction as the external wall, the central portion being bounded on opposite sides by flanks joined to the external wall, and said central portion being spaced apart from the external wall, said spacing providing on one side of the internal wall said conduit and on the other side of the internal wall the first chamber containing the desiccant.

Preferably, for ease of manufacture, the internal wall and external wall are a unitary component.

In some preferred embodiments, the internal wall is elongate in the same direction as the housing is elongate.

Preferably the internal wall has a first lip, a spacing between said first lip and the external wall defining the conduit inlet, and in some embodiments the internal wall additionally has a second lip, a spacing between said second lip and the external wall defining the conduit outlet.

Preferably the internal wall has a location feature, the position of the partition being determined by the location feature. Ideally, the location feature is an end of the internal wall.

In preferred embodiments, the partition comprises a disc, an edge of said disc being located by the location feature.

Preferably the spacing between the internal wall and the external wall that forms the conduit is arcuate and the spacing between the internal wail and the external wall that forms the first chamber is circular.

Advantageously, one end of the housing has a removable lid for gaining access to the second section in order to replace the filter, and the partition is removable from the housing in order to replace the desiccant.

Also according to a second aspect of the invention, there is provided an air conditioning condenser system, comprising a condenser unit for condensing said refrigerant and a receiver dryer for drying said condensed refrigerant, the condenser unit having a condensing section and a sub-cooling section, the sub-cooled section being positioned above the condensing section, the condenser section having a condenser section outlet positioned in a lower portion of the condenser unit and the receiver dryer having a receiver dryer inlet positioned in a lower portion of the receiver dryer for receiving condensed refrigerant from the condenser section outlet, and the sub-cooled section having a sub-cooled section inlet positioned in an upper portion of the condenser unit and the receiver dryer having a receiver dryer outlet positioned in an upper portion of the receiver dryer for providing condensed and dried refrigerant to the sub-cooled section inlet, wherein the receiver dryer is according to the first aspect of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of a condenser of an air conditioning unit with a receiver dryer unit attached; Figure 2 is an exploded perspective view of a receiver dryer unit according to a preferred embodiment of the invention; Figure 3 is a sectional view showing the interior of the receiver dryer unit of Figure 2; Figure 4 shows a preferred arrangement and shape of the integral conduit of the receiver dryer unit of Figure 3; Figure 5 is an enlarged sectional view of the filter plug assembly of the receiver dryer unit of Figure 3; and Figures 6a to 6c show various alternative cross-sectional shapes of the desiccant chamber and conduit of the receiver dryer unit of the present invention.

DETAILED DESCRIPTION

Figure 1 shows a schematic of a condenser unit 10 and receiver dryer 12 which typically form part of an air conditioning system of a motor vehicle. Refrigerant enters the condenser 10 through an inlet 14 towards the top of the unit 10. The refrigerant flows through a series of interconnected tubes (not shown) in the main body 16 of the condenser unit 10. As the refrigerant flows, it is cooled by a flow of air around the tubes. Usually, the condenser unit 10 also comprises a plurality of metal fins (not shown) that aid in the cooling process. For example, the condenser unit 10 may be a multipass-type heat exchanger of an aluminium tube and aluminium fin construction.

Liquid refrigerant then flows out of the condenser unit 10 through an outlet 18 and into a receiver dryer 12. In this example, the receiver dryer 12 is shown as a separate assembly, however, in some systems the receiver dryer 12 is integral with the condenser unit 10. After being dried and filtered, the refrigerant flows out of the receiver dryer 12 through an inlet 20 to a sub-cooled, or super-cooled, section 22.

The sub-cooled section 22 provides additional cooling for the refrigerant to improve the operation and efficiency of the air conditioning system, and it is preferable if the sub-cooled section 22 is located above the main body 16 of the condenser 10.

The refrigerant then exits the sub-cooled section 22 through an outlet 24 and passes to the next stage of the air conditioning system.

In traditional receiver dryers for air conditioning systems not having a sub-cooled section, or for systems in which the sub-cooled section is located at the bottom of the condenser, the liquid refrigerant is directed to flow down through desiccant housed within a portion of the receiver dryer unit. The refrigerant may also flow through a filter either before or after flowing through the desiccant and the refrigerant then exits the receiver dryer at the base of the unit. However, with a sub-cooled section 20 located at the top of the condenser, it is necessary for the refrigerant to exit from the receiver dryer 12 at or near the top of the unit.

Figures 2 and 3 illustrate a receiver dryer unit 12 according to the present invention.

The body or housing 26 of the receiver dryer 12 is formed from a hollow elongate tubular member such that an external wall 28 of the receiver dryer is cylindrical. In this embodiment the receiver dryer housing 26 has a circular cross-sectional shape, however, in other embodiments, the cross-sectional shape may be different, for example the receiver dryer 12 may have an oval or semi-circular cross-section, or the receiver dryer 12 may have any other suitable cross-sectional shape. The external wall 28 surrounds a substantially hollow core 30 of the receiver dryer 12.

The housing 26 of the receiver dryer 12 is divided into two sections 31, 36 along its length, as shown in Figure 3. A first section 31 is further divided into two zones, an inlet zone 32 located at a first end 34 of the housing 26 and a central zone 40.

A second section comprises an outlet zone or chamber 36 located at a second end 38 of the housing 26. The central zone 40 extends between the inlet and outlet zones 32, 36. The central zone 40 is typically significantly longer than either the inlet zone 32 or the outlet zone 36, for example the central zone 40 may be between five and ten times longer than the inlet zone 32 or the outlet zone 36, and in this way the central zone 40 extends for most of the length of the receiver dryer housing 26.

An inlet aperture 42 is located in the external wall 28 proximate the first, or lower, end 34 of the receiver dryer housing 26 such that the inlet aperture 42 opens into the inlet zone 32. The inlet aperture 42 is circular and is adapted to receive a first end of an inlet conduit 44. The inlet conduit 44 is fixed to the receiver dryer housing 26 using any suitable means, and in some embodiments, the inlet conduit 44 may be integrally formed with the external wall 28. The second end of the inlet conduit 44 attaches to the outlet 18 of the condenser unit 10. The inlet conduit 44 will typically be a rigid tubular member and will be of a suitable length to join the condenser 10 and the receiver dryer 12 in fluid communication.

An outlet aperture 46 and associated outlet conduit 48 are located proximate the second, or upper, end 38 of the receiver dryer housing 26 such that the aperture 46 opens into the outlet zone 36. The outlet aperture 46 and outlet conduit 48 will typically have an identical or a similar construction to the inlet aperture 42 and conduit 44 described above. The second end of the outlet conduit 48 attaches to the inlet 20 of the sub-cooled section 22 of the condenser unit 10.

An internal wall 50 spans the core 30 of the receiver dryer housing 26 between first 51 and second 52 points around the inner surface 54 of the external wall 28.

In particular, the internal wall 50 comprises an elongate central portion 53 having first and second ends 71, 72. The central portion 53 is bounded on opposite sides by flanks 55 (shown most clearly in Figure 6b), and the flanks 55 are joined to the external wall 28 at the first and second points 51, 52. The internal wall 50 extends substantially parallel to a longitudinal axis of the receiver dryer 12 and extends for the full length of the central section 40 of the housing 26. Preferably the internal wall 50 is integrally formed with the external wall 28 of the receiver dryer 12.

Ideally the internal 50 and external 28 walls are a unitary extrusion, and more particularly may be co-extruded in an aluminium material.

The internal wall 50 is formed together with the external wall 28 within an extrusion die (not shown) as a unitary component in an aluminium material.

The internal wall 50 divides the hollow core 30 of the receiver dryer 12 into first and second passageways or compartments 56, 58. The first compartment 56 forms a first storage chamber 56 for receiving desiccant (not shown) and excess refrigerant, and the second passageway 58 forms a conduit 58, the function of which will be described later.

The first end 71 of the internal wall 50 defines a first end or inlet 57 of the conduit 58 and is located in the first section 31 of the receiver dryer 12. The inlet 57 of the conduit 58 is, therefore, in fluid communication with the inlet zone 32. The second end 72 of the internal wall 50 defines a second end or outlet 59 of the conduit 58 and is located in the second section 36 of the receiver dryer 12. The outlet 59 of the conduit 58 is, therefore, in fluid communication with the outlet zone 36. The first and second ends 71, 72 of the internal wall 50 may include a lip feature.

The internal volume of the conduit or transport tube 58 is equal to or less than the volume of the storage chamber 56, however, preferably the internal volume of the conduit 58 is significantly less than that of the storage chamber 56.

As shown in Figure 4, and also in Figure 6b, the internal wall 50 is curved such that the conduit 58 has a crescent-shaped or arcu ate cross-sectional geometry. In this way, the storage chamber 56 retains a circular cross-sectional shape within the housing 26 of the receiver dryer 12, with the conduit 58 extending around a part of the circumference of the storage chamber 56. The functions of the storage chamber 56 and conduit 58 will be described in more detail later.

The base of the receiver dryer 12 is formed by a stamped cap 60 that is attached to the bottom edge 34 of the receiver dryer housing 26 in a brazing process. The cap 60 includes a central domed region 62 with a flange portion 64 extending radially outwards. A circular side wall 66 extends substantially perpendicularly from the edge of the flange 64 so that the wall 66 projects from the flange 64 in a direction opposite to the projection of the domed region 62, and the side wall 66 includes a lip 68 that extends radially outwards from the edge of the wall 66 furthest from the flange 64. The dimensions of the cap 60 are such that the outer diameter of the side wall 66 is equal to the inner diameter of the external wall 28 of the receiver dryer housing 26. The cap 60 can, therefore, be pushed onto the end of the housing 26 so that the domed region 62 projects into the inlet zone 32 of the receiver dryer 12, and the lip 68 abuts the bottom edge 34 of the tubular external wall 28.

Although the base cap 60 is shown as dome-shaped in this embodiment, the cap may be of any suitable shape so as to withstand the pressure within the receiver dryer 12, which is typically around 20 bar (2000 kPa).

A filter plug assembly 70 is used to seal the second, upper end 38 of the receiver dryer housing 26 as well as an upper end of the storage chamber 56, as shown most clearly in Figure 5. The filter plug assembly 70 comprises first and second capping members 74, 76 and a filter housing 78 (Figure 2) extending between the first and second capping members 74, 76 and supporting a filter 80.

The first capping member 74 comprises a circular, disc-shaped plate 82 and a flange 84 extending around the periphery of the plate 82 and projecting perpendicularly from the plate 82. A circumferential groove or channel 86 is formed in the outer surface of the flange 84. The channel 86 is sized to house an 0-ring 88 such that part of the 0-ring 88 projects from the surface of the flange 84.

As such, the 0-ring forms an upper sealing means 88 of the filter plug assembly 70.

The second capping member 76 also comprises a circular, disc-shaped plate 90.

A circular wall 92 projects perpendicularly from one face of the plate 90. The circular wall 92 has a smaller diameter than the plate 90 and the wall 92 is positioned such that the centres of the two circles are offset and the outer face of the wall 92 is aligned with the edge of the plate 90 around a portion of its length.

As such, a portion of the plate 90 extends beyond the wall 92 and forms a crescent-shaped lip 94. A channel 86' is formed in the outer surface of the wall 92. This channel 86' is similar to the channel 86 described above, and is sized to house a second 0-ring 88' so as to form a lower sealing means 88' of the filter plug assembly 70.

In the filter plug assembly 70, the capping members 74, 76 are arranged at opposing ends such that the plates 82, 90 lie parallel but spaced apart from each other, and the flange 84 and wall 92 extend in opposite directions and away from each other. A filter 80 is sandwiched between the plates 82, 90. The filter may be of any type or construction as is well known in the art. It may be desirable, in some embodiments of the invention, to support the filter 80 in a filter housing 78.

The filter housing 78 may be in the form of a frame or a cage or similar that supports and retains the filter 80 between the plates 82, 90. -11 -

The diameter of the second capping member 76 is less than the diameter of the first capping member 74. In particular, the outer diameter of the first capping member 74 is approximately equal to the inner diameter of the cylindrical external wall 28 of the receiver dryer housing 26, and the outer diameter of the wall 92 of the second capping member 76 is approximately equal to the inner diameter of the storage chamber 56.

As such, when the filter plug assembly 70 is pushed into the second end 38 of the receiver dryer housing 26, the upper sealing means 88 of the first capping member 74 forms a seal against the inner surface of the external wall 28 of the receiver dryer 12. Additionally, the wall 92 of the second capping member 76 extends into an end portion of the storage chamber 56 and the lower sealing means 88' forms a seal against the inner surface of the storage chamber 56. As such the second capping member 76 forms a partition between the first and second sections 31, 36 of the receiver dryer 12, and in particular between the storage chamber 56 and the outlet zone 36. When the filter plug assembly 70 is fully inserted into the receiver dryer 12, the lip 94 of the plate 90 is seated on the second end 72 of the internal wall 50, and as such, the second end 72 of the wall 50 acts as a location feature for the second capping member 76.

To retain the filter plug assembly 70 in position, a retaining means 96 is inserted in the end 38 of the receiver dryer housing 26. In this embodiment, the retaining means is a C-clip 96 that locates on the edge of the flange 84. The C-clip 96 is outwardly biased so that the C-clip 96 presses against the inner surface of the wall 28 of the receiver dryer 12. In some embodiments it may be preferable to provide a groove or recess in the surface of the wall 28 such that a portion of the retaining means 96 locates in the groove.

In use, before the filter plug assembly has been inserted, the storage chamber 56 is filled with a desiccant material (not shown). Because the bottom of the storage chamber 56 is open, the desiccant material will at least partially fill the inlet zone 32 of the receiver dryer 12. Some desiccant material may also pass into the lower end of the conduit 58; however, if filled in this way the majority of the conduit 58 should remain free of desiccant material. Once the storage chamber 56 has been filled, the filter plug assembly 70 can be inserted as described above.

The receiver dryer is assembly to the main condenser without the plastic cap (with o-rings) and without the desiccant inside. This is brazed in a furnace, and afterwards the desiccant bag is loaded into the receiver dryer and then the plastic filter plug assembled.

In operation, refrigerant flows from a lower portion of the condenser 10 into the inlet zone 32 of the receiver dryer 12. Upon entering the receiver dryer 12, the refrigerant comes into contact with at least a portion of the desiccant held within the storage chamber 56 and inlet zone 32, which acts to remove water from the refrigerant. The liquid refrigerant is then enters the conduit 58 via the inlet 57 and is forced to flow up the conduit 58 due to the pressure in the system. The conduit 58 is straight and unobstructed by any features within the conduit so that the flow of refrigerant is continuous and uninterrupted for the full length of the conduit. At the top or outlet 59 of the conduit 58 the refrigerant enters the outlet zone 36 and passes through the filter 80 held between the first and second capping members 74, 76. The filter removes any debris in the refrigerant before the liquid flows out of the receiver dryer through the aperture 46 and into the sub-cooled section 22 of the condenser unit 10.

Any excess refrigerant in the system is held within the storage chamber 56 of the receiver dryer 12. In this way, the storage chamber 56 is typically at least partially filled with refrigerant in addition to the desiccant material.

In some embodiments, the filter plug assembly 70 may be separable such that each of the first capping member 74, filter housing 78 and second capping member 76 can be separated. This allows the first capping member 74 and filter housing 78 to be withdrawn from the housing 26 of the receiver dryer 12 when it is necessary to replace or clean the filter 80, with the second capping member 76 remaining in position as a partition. The second capping member 76 may additionally be removed when it is necessary to replace the desiccant within the storage chamber 56.

In a preferred embodiment, the receiver dryer 12 includes a cylindrical storage chamber 56 and an arcuate conduit 58 located to one side of the storage chamber 56. In other embodiments it may be preferable if the storage chamber 56 and conduit 58 have different cross-sectional shapes. Two examples are shown in Figures 6a and 6c (Figure 6b is a view of the preferred embodiment for comparison).

In the example shown in Figure 6a, the storage chamber 56' has approximately the same cross-sectional area as the conduit 58'. In this case the internal wall 50' spans the housing of the receiver dryer across the diameter so as to form two semi-circular passageways. In Figure 6c, the conduit 58" has a circular cross-sectional shape and protrudes into a larger storage chamber 56".

In addition, in the embodiment shown in Figures 3 and 4, the thickness of the internal 50 and external 28 walls of the receiver dryer 12 are equal. However, in other embodiments it may be preferable if the internal wall 50 is thinner than the external waIl 28, as shown for example in Figure 6c.

The receiver dryer of the present invention has a number of advantages over known devices.

Firstly, because the conduit is integrally formed with the housing of the receiver dryer by co-extrusion of the internal and external walls, the receiver dryer is less complex and has fewer parts then conventional receiver dryers.

Secondly, co-extrusion process means that it is easy to adapt the relative volumes of the storage chamber and conduit by changing the shape of the extrusion die to alter the location and shape of the internal wall. This allows the receiver dryer to -14 -be easily adapted to accommodate different volumes and flow rates of refrigerant, depending on the system requirements.

The provision of a removable filter plug assembly allows the filter to be removed and replaced easily, during regular servicing of the air conditioning system, without the need to drain the system or fully detach the receiver dryer from the condenser unit.

The invention therefore provides an improved receiver dryer for use in an air conditioning system.

Claims

CLAIMS1. A receiver dryer for an air conditioning system for use with a condenser unit having a lower condenser section and an upper super-cooling section, the receiver dryer comprising: -an elongate housing, said housing having opposite ends and an external wall that extends between said ends; -an inlet positioned in a first section of the housing for receiving condensed refrigerant from said lower condenser section of a condenser unit; -an outlet positioned in a second section of the housing for providing dried condensed refrigerant to said upper sub-cooling section of a condenser unit; -a partition dividing the first section from the second section such that, in use, the second section is above the first section; -a first chamber in said first section containing a desiccant for drying the refrigerant received from the inlet; -a second chamber in said second section containing a filter for filtering said dried condensed refrigerant provided to the outlet; -a conduit, the conduit having a conduit inlet inside the first chamber for receiving said condensed refrigerant from the first chamber and a conduit outlet inside the second chamber for conveying said received condensed refrigerant upwards past the partition from the first chamber into the second chamber; wherein the housing has within the external wall an internal wall, the internal wall having an elongate central portion extending in the same direction as the external wall, the central portion being bounded on opposite sides by flanks joined to the external wall, and said central portion being spaced apart from the external wall, said spacing providing on one side of the internal wall said conduit and on the other side of the internal wall the first chamber containing the desiccant.
2. A receiver dryer as claimed in Claim 1, in which the internal wall and external wall are a unitary extrusion.
3. A receiver dryer as claimed in Claim I or Claim 2, in which the internal wall is elongate in the same direction as the housing is elongate.
4. A receiver dryer as claimed in any preceding claim, in which the internal wall has a first lip, a spacing between said first lip and the external wall defining the conduit inlet.
5. A receiver dryer as claimed in Claim 4, in which the internal wall has a second lip, a spacing between said second lip and the external wall defining the conduit outlet.
6. A receiver dryer as claimed in any preceding claim, in which the internal wall has a location feature, the position of the partition being determined by the location feature.
7. A receiver dryer as claimed in Claim 6, in which the location feature is an end of the internal wall.
8. A receiver dryer as claimed in Claim 6 or Claim 7 in which the partition comprises a disc, an edge of said disc being located by the location feature.
9. A receiver dryer as claimed in any preceding claim, in which the spacing between the internal wall and the external wall that forms the conduit is arcuate and the spacing between the internal wall and the external wall that forms the first chamber is circular.
10. A receiver dryer as claimed in any preceding claim, in which one end of the housing has a removable lid for gaining access to the second section in order to replace the filter, and the partition is removable from the housing in order to replace the desiccant.
11. An air conditioning condenser system, comprising a condenser unit for condensing said refrigerant and a receiver dryer for drying said condensed refrigerant, the condenser unit having a condensing section and a sub-cooling section, the sub-cooled section being positioned above the condensing section, the condenser section having a condenser section outlet positioned in a lower portion of the condenser unit and the receiver dryer having a receiver dryer inlet positioned in a lower portion of the receiver dryer for receiving condensed refrigerant from the condenser section outlet, and the sub-cooled section having a sub-cooled section inlet positioned in an upper portion of the condenser unit and the receiver dryer having a receiver dryer outlet positioned in an upper portion of the receiver dryer for providing condensed and dried refrigerant to the sub-cooled section inlet, wherein the receiver dryer is as claimed in any preceding claim.
12. A receiver dryer substantially as herein described, with reference to or as shown in the accompanying drawings.
13. An air conditioning condenser system having a receiver dryer, substantially as herein described, with reference to or as shown in the accompanying drawings.